I bought this blower,
https://www.sparkfun.com/products/16858
but the fan barely spins when I apply 12V power to the red and black wires.
I didn’t notice that it uses a “pulse-width-modulated (PWM) system” on the yellow wire.
What part do I need so I can send a full strength PWM signal on the yellow wire to make the fan spin at full speed?
Hi James,
Tie the PWM line to 12V and it should run at full speed.
Cheers!
-Bill
Hi Bill, thanks for the message. I think this fan is defective maybe? Please check this video I made:
The other fan is this one, which has a far smaller CFM rating but clearly blows much harder:
I may have made a mistake with the 12V on the PWM line. It looks like 5V may be what’s needed.
That said, the data sheet says the fan should run at full speed when the PWM control is disconnect. Since your fan didn’t run properly when you did that, it’s possible that it’s defective.
-Bill